Role of Sleep Reactivity in Shift Work Disorder

Conditions

• Shift-work Disorder

Eligibility Criteria

Sex

ALL

Age

18 Years - N/A

Healthy Volunteers

Not accepted

Interventions

• Active phototherapy — BEHAVIORAL
  Timed bright light exposure delivered in a controlled laboratory setting (10,000 photopic lux) designed to delay the DLMO to 4 am or later.
• Control phototherapy — BEHAVIORAL
  Timed less intense light exposure delivered in a controlled laboratory setting (100 photopic lux) that still has a perceptible alerting effect but is not designed to shift circadian phase.
• Cognitive Behavioral Therapy (CBT) — BEHAVIORAL
  Cognitive strategies will identify stressors (e.g., dysfunctional beliefs about sleep) and intervene on worry and rumination with cognitive reappraisal and active coping. Sessions will be conducted by a trained behavioral sleep medicine provider via telemedicine to increase accessibility.
• Sleep education control — BEHAVIORAL
  Sleep duration recommendations will be equivalent to the CBT group (8 hours of sleep opportunity) to ensure that outcomes are not confounded by time in bed. Materials in the sleep education control condition will be separated into weekly electronic materials monitored for engagement and completion.

Study Details

The purpose of this project is to test sleep reactivity as an independent cause of Shift Work Disorder (SWD). The primary hypothesis is that those with high sleep reactivity will show persistent SWD symptoms after experimental reduction of circadian misalignment, which will then be mitigated with CBT.

Key Dates

Start date

Jan 1, 2023

Status verified

Oct 2025

Primary completion

Jun 30, 2027

Completion

Oct 1, 2027

Study Design

Enrollment

150 participants (estimated)

Allocation

RANDOMIZED

Intervention model

SEQUENTIAL

Primary purpose

OTHER

Arms

• Experimental: Active light condition
  Timed bright light exposure will be delivered in a controlled laboratory setting (10,000 lux) designed to delay the DLMO to 4 am or later. This would shift the circadian nadir (e.g., the period of maximal sleepiness) into the typical daytime sleep period after the nightshift (i.e., circadian nadir at \~10am). Bright light will be delivered in a controlled lab environment using a full spectrum light-box with UV filter (Sunbox Sunray II) to achieve a robust reduction of circadian misalignment. The light schedule will be tailored to each individual nightshift worker, determined by: 1) their baseline circadian phase, and 2) the human phase response curve adjusted to the individual's baseline circadian phase.
• Active Comparator: Control light condition
  Shift workers randomized to the control condition will receive less intense light that still has a perceptible alerting effect (100 photopic lux). However, light will occur during a portion of the phase response curve with minimal phase shifts.
• Experimental: Cognitive Behavioral Therapy (CBT) condition
  The CBT condition will probe sleep reactivity using validated CBT strategies over 6 sessions in accordance with the two-factor theory of emotion. Behavioral strategies will be used to reduce physiological arousal (e.g., relaxation training, breathing) and to strengthen behavioral cues for sleep (e.g., sleep hygiene and sleep scheduling). Sleep times will be scheduled to align with the reduced circadian misalignment (compromised phase position, i.e., maintaining a slightly delayed sleep period on offwork days). Cognitive strategies will identify stressors (e.g., dysfunctional beliefs about sleep) and intervene on worry and rumination with cognitive reappraisal and active coping. Sessions will be conducted by a trained behavioral sleep medicine provider via telemedicine to increase accessibility.
• Active Comparator: Sleep education control condition
  This condition will use an established sleep education control protocol modified for nightshift workers based on the "Plain Language about Shiftwork" published by the National Institute for Occupational Safety and Health (NIOSH). Sleep duration recommendations will be equivalent to the CBT group (8 hours of sleep opportunity) to ensure that outcomes are not confounded by time in bed. Materials in the sleep education control condition will be separated into weekly electronic materials monitored for engagement and completion.

Primary Outcome Measure

Dim light melatonin onset [ Time Frame: Within two days of treatment for a duration of 24 hours ]

Central Contacts

• Philip Cheng, PhD
  248-344-7361
  [email protected]
• Marleigh Treger, BS
  248-344-8028
  [email protected]

Locations (1)

Find similar trials in Novi, MI

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